The present application is directed to manufacturing processes, and more particularly to creating sharp pointed tips that are carried on substrates, including but not limited to field emission tips found on flexible substrates.
Presently sharp tip structures used, for example, as field emission devices are commonly “Spindt tip” type structures manufactured by the use of conventional lithographic techniques. More recently the use of carbon tubes has been suggested as a building block for the manufacture of such tips.
A ‘Spindt tip’ has a conical tip structure micro-fabricated on a substrate, which emits electrons by field emission. These tips have a relatively sharp apex, and are capable of creating a high electric field at a relatively low voltage, which results in the emission of significant amounts of current at relatively low gate voltages (e.g., less than 100 V). The use of lithographic manufacturing techniques means individual tips (i.e., emitters) allows for the tips to be packed close together, so that the average (or “macroscopic”) current density obtained from a Spindt array can be as much as 2×107 A/m2.
However, present manufacturing techniques are both time consuming and costly. It is therefore considered useful to develop a low cost manufacturing process capable of forming sharp tips for use in field emission displays, microscopy, and other field emission environments as well as for other no filed emission applications.